http://nycedc.tumblr.com/post/16175652438/ratio-of-single-men-to-single-women-in-nyc-new
It looks in more detail at the sex ratio in New York City, and attempts to debunk the "myth" that there are so many more women than men living there. A cursory look at the numbers across most of Manhattan, however, combined with the realization that leaving Manhattan isn't very common for those who live there, seems to actually support the stereotype. In any case, have a look:
If I were a single girl living in Manhattan, I would do everything I could to aggressively suppress my Sex-and-The-City-induced romantic notions of "city life" and get the hell out of there.